What is callback function in JavaScript

Question

What is the use of callback function used in angularjs? Does it play any important role in designing web page?

Answer 1

• callback is not a keyword, its just a name of parameter that is passed into the function, you can call it whatever you want (callback or cb is pretty common).

• Callback function is a function which is passed to a function as parameter and is executed when the outer function is completed.
•  Callbacks are a feature of JavaScript not particularly angularjs. Its a way to send a function as a parameter to the callee so that the callee call that function once the task is finished.
• Example of callback function:

  function useAsCallback(string){
    console.log("callback is being executed with passed parameter: " + string)
  }
  
  function main(param, callback){
    callback(param)
  }
  
  main(123456, useAsCallback)

• I found this website to be useful for learning ANGULARJS . Have a look at the site. Hope it helps.    https://www.edureka.co/masters-program/full-stack-developer-training